Lensing Effect for Stars Near Sagittarius A*

Hi Stoat,

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Stoat</i>
<br />Hi Thomas, we were just talking about the star S2 which gets into about 180 a.u. of the super massive object. What are your thoughts on it? It's fifteen solar masses, so it can't be very old.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I can't see the stars surrounding the supermassive object getting very old. Their orbits will be disturbed so much by their mutual close encounters that eventually they will fall into the central object. They will then either be replaced by other stars being captured or by new stars forming in the region.


<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Stoat</i>
It must be distorted by its close approach, why doesn't it explode?
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I doubt that it will be distorted much, but even if, why should they explode then?. There are double stars that are orbiting much more closely and that are distorted so much that material flows from one to the other, yet still they don't explode. Stars are just balls of plasma (basically protons and electrons) with a luminous atmosphere (see my page www.plasmaphysics.org.uk/research/sun.htm ).

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Stoat</i>
Also, what do you make of the idea of a neutrino ball?
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You mean for the central object? I don't know about the theory of neutrino stars, but as far as I am concerned, it can as well be just normal matter. If you take the theory under the link I gave above and also at www.plasmaphysics.org.uk/research/starformation.htm , then it should be evident that even an object with a mass of a few million masses will be stable in equilibrium.
The point is that such massive objects will have such a high temperature due to the associated gravitational energy (as shown under the above links) that there will be very little light emitted in the visible region. Most of it will be x-rays and gamma-rays. This is why you don't see the central object in the visible and infrared. However, in x-rays the central object is visible (see apod.nasa.gov/apod/ap000120.html ) i.e. it is not a black hole (although other people may argue that it is just the surrounding gas that is emitting the x-rays).

Thomas

Hi Thomas, I#'d be very interested in hearing your ideas on the temperature at the Schwarchild radius. Is it gravitationally "hot" but e.m. cold for instance? What do you make of it when it's slung into the lorentzian, as t_r/t = sqrt(1 - r_s/r)

I wonder if it's possible that the elliptical orbit of S2 is a relativistically altered parabolic trajectory? As far as I know, the theory of what's bringing stars in is another super massive black hole. i haven't looked at the masses of the other close stars but they all look like big brutes. They burn their fuel fast, and they'll already will have a lot of heavier elements. Are sol mass stars eaten or flung out? do massive stars have time to come in from the galactic halo? That question of the rosetta orbit of S2 also intrigues me.

I suppose we could wait and see but all this talk of neutrino balls suggests to me at any rate that the physics near the galactic centre is going to hammered into an Einstein model at whatever cost.

Anyway, a parabolic trajectory, capture or escape trajectory, v = sqrt(2GM/r) the same as the Scwartzchild radius equation where v is c. We can also throw 2GM/rc^2 into the lorentzian.

I do think that metaresearch should do some work on this, rather than wait.

In researching S2(the object said to be nearest the galatic center) it seems Kepler's model is being used to determine most of data rather than observations. The observations are made in just a small part of the spectrum and in very narrow window less than a few arcsec in diameter. Can you tell how so much can be determined about those objects by so little observed data points? Is it not like reading tea leaves or grasping at straws? I think a lot can be learned from observing the galatic center but using a model to determine what the observations are is not very bright.

Hi Jim, no it is real data. They've got the complete orbit of S2 but we'll have to wait for more data for other star orbits. Not long though, as they're really motoring round. A fifteen year orbit for S2, it's doing about two percent of light speed!

Sloat, Maybe the data indicates a star in an orbit but its not at all clear that is the truth from just data. The data is being fitted to the Kepler model-you can clearly see this if care is taken in reading the article. Its so small a sample of spectral data they had to reject a lot of data that didnot fit within the model. All in all not a good way to do science although lots a science is done this way. Hopefully in the future some thought will be given to observed details that don't fit the whatever favored model is used. I ask you how is this practice any different than what was done a 1,000 years ago?